System and method of multiplexing data from multiple ports

ABSTRACT

Telecommunication equipment of the present invention includes a switch for receiving data from a plurality of ports and inserting a unique port identifier in the data from each port to identify the source port of the data. The equipment also includes a multiplexer coupled to the switch and operable to multiplex the data from the plurality of ports into a single serial data stream. A method of the present invention includes the steps of receiving data from a plurality of ports, adding a unique port identifier to the data from each port to identify the port from which the data came, and multiplexing the data from the plurality of ports into a single data stream for transmission.

TECHNICAL FIELD OF THE INVENTION

[0001] This invention relates to telecommunications network andequipment, and more particularly, to a system and method of multiplexingdata from multiple ports.

BACKGROUND OF THE INVENTION

[0002] The optical subscriber terminal is a customer premise equipment(CPE) that aggregates and transports both Ethernet and time-divisionmultiplexed (TDM) customer traffic to and from a network routing deviceand the network beyond. Customer Ethernet traffic may include data at 10Mb/s, 100 Mb/s or higher rates from customers' Ethernet local areanetworks, while TDM data may consist of data at DS3 (or STS-1) and T1speeds. The customer traffic is aggregated into an optical uplink fortransmission to the network routing device.

[0003] Typically, data from the Ethernet ports are multiplexed at thephysical layer into multiple respective SONET STS-1 synchronous payloadenvelopes (SPEs) as a serial data stream. The serial data stream isconverted into a SONET optical signal for transmission to the networkrouting device. The network routing device demulitplexes the serial datastream to recover data from each individual Ethernet port for processingby higher layer network equipment such as routers. This conventionalmethod is inefficient in bandwidth utilization, because the data fromeach port is mapped into its respective SPE. The conventional methodalso requires substantial processing in the higher layer networkequipment such as routers.

SUMMARY OF THE INVENTION

[0004] It may be seen that there is a need for a more efficient systemand method of multiplexing data from several Ethernet ports at customerpremises equipment for transport to a telecommunication network.

[0005] In accordance with an embodiment of the present invention,telecommunication equipment includes a switch for receiving data from aplurality of ports and inserting a unique port identifier in the datafrom each port to identify the source port of the data. The equipmentalso includes a multiplexer coupled to the switch and operable tomultiplex the data from the plurality of ports into a single serial datastream.

[0006] In accordance with another embodiment of the present invention, amethod includes the steps of receiving data from a plurality of ports,adding a unique port identifier to the data from each port to identifythe port from which the data came, and multiplexing the data from theplurality of ports into a single data stream for transmission.

[0007] In accordance with yet another embodiment of the presentinvention, a method of multiplexing data from a plurality of ports fortransmission includes the steps of receiving data from the plurality ofports, adding a unique port identifier to a predetermined header fieldof the data from each port to identify the port from which the datacame, multiplexing the data from the plurality of ports into a singleSONET synchronous payload envelope, and converting the multiplexed datainto a SONET optical signal for transmission.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] For a more complete understanding of the present invention, theobjects and advantages thereof, reference is now made to the followingdescriptions taken in connection with the accompanying drawings inwhich:

[0009]FIG. 1 is simplified block diagram of an embodiment of customerpremise equipment operable to multiplex data from multiple ports into asingle synchronous payload envelope according to the teachings of thepresent invention;

[0010]FIG. 2 is a more detailed block diagram of an embodiment ofcustomer premise equipment operable to multiplex data from multipleEthernet ports into a single synchronous payload envelope according tothe teachings of the present invention; and

[0011]FIG. 3 is a diagram showing an embodiment of a tagged media accesscontrol (MAC) frame with the VLAN tag field used according to theteachings of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0012] The preferred embodiment of the present invention and itsadvantages are best understood by referring to FIGS. 1 through 3 of thedrawings, like numerals being used for like and corresponding parts ofthe various drawings.

[0013]FIG. 1 is simplified block diagram of an embodiment of customerpremise equipment 10 operable to multiplex data from multiple ports intoa single synchronous payload envelope (SPE) according to the teachingsof the present invention. Equipment 10 receives data from a plurality ofports 14 carrying data, such as Ethernet ports. Ethernet ports 14 maycarry data at 10 Mb/s, 100 Mb/s, or higher rates. Equipment 10 includesa multiplexer device 12, which receives the data from the multipleEthernet ports 14 and inserts a unique port identifier or tagidentifying the source port the data originated. The tag is insertedinto a predetermined data field in the header of the data. For example,a source port identifier tag may be inserted into a predetermined fieldin the Ethernet frame tag header. Multiplexer device 12 multiplexes thedata from the multiple Ethernet ports into a single SPE transmitted as aserial data stream 16 to a telecommunication network (not shown). Forexample, serial data stream 16 may have SONET formatting in which datatraffic from all the ports are multiplexed into a single SONET SPEinstead of the data from each port being mapped into its own respectiveSPE. Bandwidth efficiencies are thus achieved.

[0014]FIG. 2 is a more detailed block diagram of an embodiment ofcustomer premise equipment 22 operable to multiplex data from multipleEthernet ports 14 into a single synchronous payload envelope accordingto the teachings of the present invention. Equipment 22 includes anEthernet interface circuit 26 which receives data from multiple Ethernetports. Ethernet interface circuit 26 includes transceivers, transformersand protection circuits as known in the art. A switch 28 receives thedata from the plurality of ports and performs the primary functions ofperforming media access control, tagging all Ethernet frames with uniquetags, and passing the tagged frames to a multiplexer/demultiplexer 30.Multiplexer/demultiplexer 30 then multiplexes the traffic into a singleSONET STS21C SPE 16 for conversion to optical signals and transmissionto a network routing device.

[0015] Referring to FIG. 3, a diagram showing an embodiment of a taggedmedia access control (MAC) frame 40 with a virtual local area network(VLAN) tag field 46 to be used according to the teachings of the presentinvention is shown. The tagged MAC frame format is described in detailin ANSI/IEEE Standard 802.3, 2000 Edition, Local and Metropolitan AreaNetworks—Part 3: Carrier Sense Multiple Access with Collision Detection(CSMA/CD) Access Method and Physical Layer Specifications. Tagged MACframe 40 includes a number of fields, including a tag controlinformation (TCI) field 41. Tag control information field 41 includes a3-bit user priority field 42, a 1-bit canonical format indicator (CFI)field 44, and a 12-bit VLAN identifier (VID) field 46. As described inthe IEEE Standard 802.3, the VID field is used to identify the virtualLAN that the frame belongs to. A virtual LAN is a logical identificationof a logical segment of a LAN representing a broadcast domain. VirtualLANs are identified to reduce the traffic on the LAN because broadcastand multicast messages may be sent to users on the virtual LAN ratherthan the entire LAN. The VID is therefore traditionally used to identifythe VLAN to which the sender and receiver of the data belong.

[0016] The present invention provides a different use of the VID fieldby inserting a unique tag or identifier to identify the source Ethernetport of the data. An optical subscriber access multiplexer 24 receivingthe optical uplink traffic from customer premises equipment 22 includesa multiplexer/demultiplexer 34 that demultiplexes the serial data streamto recover each individual Ethernet port data based on the source portidentifier or tag in VID field 46, and provides the data to a routingdevice 36. Routing device 36 routes the traffic based on the source portidentifier, MAC address and IP address to its output 38. Because theidentification of an Ethernet port in effect identifies a servicesubscriber, it is also possible to transmit and process the data trafficaccording to the subscriber service level agreement (SLA) and quality ofservice (QoS).

[0017] In the reverse direction, routing device 36 receives data andadds the unique source port tag based on the source IP address of thesending device of the data. Multiplexer/demultiplexer 34 thenmultiplexes the data into an STS21C SPE for transmission to equipment22. Multiplexer/demultiplexer 30 of equipment 22 demultiplexes the SPEto produce an output to switch 28. Based on the source port tag, switch28 switches the data to the proper destination Ethernet port 14.

[0018] While the invention has been particularly shown and described bythe foregoing detailed description, it will be understood by thoseskilled in the art that various changes, alterations, modifications,mutations and derivations in form and detail may be made withoutdeparting from the spirit and scope of the invention.

What is claimed is:
 1. A telecommunication equipment, comprising: aswitch receiving data from a plurality of ports and operable to insert aunique port identifier in the data from each port to identify the sourceport of the data; and a multiplexer coupled to the switch and operableto multiplex the data from the plurality of ports into a single serialdata stream.
 2. The telecommunication equipment, as set forth in claim1, wherein the switch receives data frames from a plurality of Ethernetports.
 3. The telecommunication equipment, as set forth in claim 1,wherein the multiplexer is operable to multiplex the data from theplurality of ports into a single SONET synchronous payload envelope. 4.The telecommunication equipment, as set forth in claim 1, wherein themultiplexer is operable to convert the single serial data stream intooptical signals.
 5. The telecommunication equipment, as set forth inclaim 1, further comprising a subscriber access multiplexer operable toreceive the single serial data stream from the multiplexer, demultiplexthe serial data stream into data from each port, and route the databased on the unique port identifier.
 6. The telecommunication equipment,as set forth in claim 1, wherein the switch is operable to insert theunique port identifier into a VID data field of a tagged MAC frame ofthe data from each port.
 7. The telecommunication equipment, as setforth in claim 1, further comprising: a subscriber access multiplexeroperable to receive data from a plurality of sender nodes in a networkand operable to insert the unique port identifier based on an IP addressof the sender node of the data, and multiplex the data into a singleserial data stream; the multiplexer being operable to receive the singleserial data stream from the subscriber access multiplexer anddemultiplex the data; and the switch being operable to switch thedemultiplexed data based on the unique port identifier to the pluralityof ports.
 8. The telecommunication equipment, as set forth in claim 1,further comprising a subscriber access multiplexer operable to receivethe single serial data stream from the multiplexer and route the data toa destination network node based on the unique port identifier, a MACaddress and IP address in the data.
 9. A method comprising: receivingdata from a plurality of ports; adding a unique port identifier to thedata from each port to identify the port from which the data came; andmultiplexing the data from the plurality of ports into a single datastream for transmission.
 10. The method, as set forth in claim 9,wherein receiving data comprises receiving data from a plurality ofEthernet ports.
 11. The method, as set forth in claim 9, whereinmultiplexing the data comprises multiplexing the data into a singleSONET synchronous payload envelope.
 12. The method, as set forth inclaim 9, wherein adding the unique port identifier comprises insertingthe unique port identifier into a VID field of a tagged MAC frame of thedata.
 13. The method, as set forth in claim 9, further comprisingconverting the single serial data stream into SONET optical signals fortransmission.
 14. The method, as set forth in claim 9, furthercomprising: receiving the single serial data stream; demultiplexing thesingle serial data stream into data from each port; and routing the datafrom each port based on the unique port identifier.
 15. The method, asset forth in claim 9, further comprising: receiving data from aplurality of sender nodes in a network; inserting a unique portidentifier based on an IP address of the sender node of the data; andmultiplexing the data into a single serial data stream for transmission;receiving the transmitted data and demultiplexing the data into datafrom each sender node; and switching the demultiplexed data based on theunique port identifier to the plurality of ports.
 16. The method, as setforth in claim 9, further comprising receiving the single serial datastream and routing the data to a destination network node based on theunique port identifier, a MAC address and IP address in the data.
 17. Amethod of multiplexing data from a plurality of ports for transmission,comprising: receiving data from the plurality of ports; adding a uniqueport identifier to a predetermined header field of the data from eachport to identify the port from which the data came; multiplexing thedata from the plurality of ports into a single SONET synchronous payloadenvelope; and converting the multiplexed data into a SONET opticalsignal for transmission.
 18. The method, as set forth in claim 17,wherein receiving data comprises receiving data from a plurality ofEthernet ports.
 19. The method, as set forth in claim 17, wherein addingthe unique port identifier comprises inserting the unique portidentifier into a VID field of a tagged MAC frame of the data.
 20. Themethod, as set forth in claim 17, further comprising: receiving theSONET optical signal and converting to a single data stream;demultiplexing the data stream from each port; and routing the data fromeach port based on the unique port identifier.
 21. The method, as setforth in claim 17, further comprising: receiving data from a pluralityof sender nodes in a network; inserting a unique port identifier basedon an IP address of the sender node of the data; multiplexing the datainto a single serial data stream for transmission; receiving thetransmitted data and demultiplexing the data into data from each sendernode; and switching the demultiplexed data based on the unique portidentifier to the plurality of ports.
 22. The method, as set forth inclaim 17, further comprising receiving the single serial data stream androuting the data to a destination network node based on the unique portidentifier, a MAC address and IP address in the data.